1. Field of the Invention
The present invention relates to gas discharge display devices, especially to those utilizing D.C. type gas discharging.
2. Description of the Prior Art
Among D.C. type gas-discharge display devices, a typical known one is the gas discharge display device of the Burroughs type which utilizes so-called self-scanning. As shown in FIG. 1, the abovementioned self-scanning type gas discharge display device comprises a vertical array of parallel cathodes K.sub.1, K.sub.2, . . . , a horizontal array of parallel anodes A.sub.1, A.sub.2, . . . for displaying and scanning anodes S.sub.1, S.sub.2, . . . which are disposed in parallel to the displaying anodes A.sub.1, A.sub.2, . . . , wherein the cathodes K.sub.1, K.sub.2, . . . are disposed crosswise to the anodes A.sub.1, A.sub.2, . . . and S.sub.1, S.sub.2, . . . forming small discharge gaps inbetween. The cathodes K.sub.1, K.sub.2, . . . are divided into several divided parts, for example, a first part of K.sub.1 to K.sub.5, a second part of K.sub.6 to K.sub.10, a third part of K.sub.11 to K.sub.15 and so on, as shown in FIG. 1. The cathodes of the corresponding order in the divided parts are connected in common, thereby forming a group of a first phase cathode K.phi..sub.1, a group of a second phase cathodes K.phi..sub.2, . . . . The abovementioned self-scanning type gas discharge display device is operated by applying cyclic pulse signals K.phi..sub.1, K.phi..sub.2, . . . having timings as shown in FIG. 2 to the groups of respective phase cathodes K.phi..sub.1, K.phi..sub.2, . . . . By application of such cyclic signals to the cathode groups, scanning glow discharge is sequentially transferred along a selected one scanning anode (S.sub.1 or S.sub.2, . . . ) from a starting cathode K.sub.R to the cathode K.sub.1 and sequentially thereafter, through K.sub.2, . . . K.sub.5, K.sub.6, . . . K.sub.10, K.sub.11, . . . K.sub.15, . . . . By application of a display voltage signal to a selected display anode during the time period when the pulse signal to form the small glow discharge is impressed on a selected cathode, a display with a display glow discharging is made at the cross point of the selected display anode and the selected cathode.
The gas discharge display device of the abovementioned conventional type has an advantage that an electronic circuit for the scanning of the cathode can be made simple, since the array of cathodes is divided into several divided arrays. However, on the other hand, the abovementioned conventional device has such a grave problem of a possibility of erroneous scanning. Such erroneous scanning is likely to happen in a manner that the scanning glow discharging erroneously is transferred, instead of to the next position, to an apart position, the cathode of which belongs to the same phase of cathodes. The abovementioned erroneous scanning results in very unstable operation and hence fatal erroneous displaying.